In recent years, research and development for an image watching method etc. have been carried out not only for a two-dimensional image but also for a three-dimensional image.
For example, Patent Literature 1 describes a stereoscopic watching method. According to the stereoscopic watching method, an image is given a three-dimensional appearance in such a manner that (i) two-dimensional data for a left eye and two-dimensional data for a right eye are displayed time-divisionally on an identical display screen and (ii) left and right lenses of a pair of glasses having opening and closing functions, which glasses are worn by a viewer, are opened and closed in synchronization with displaying of the two-dimensional data for the left eye and of the two-dimensional data for the right eye.
Patent Literature 2 describes a multi-image system. According to the multi-image system, (i) images of different kinds are displayed on an identical display screen, and (ii) each of a plurality of viewers in an identical room can watch a corresponding one of the images of different kinds.
Patent Literature 3 describes an image display device. According to the image display device, a plurality of images are displayed on an identical display screen without reducing a display size of each of the plurality of images, and thereby a plurality of viewers simultaneously watch the plurality of images.